String replacement problems...

Hi I am trying to figure out how to get ereg_replace / preg_replace to replace a match only once. Here is my example: $text = "[foo] bah [foo] moo [foo] boo\n"; $ans = ereg_replace("\[foo\]{1}","FOO",$text); or $ans = preg_replace("/\[foo\]{1}/",$text,"FOO"); The answer I get for both I run the example echo $ans; FOO bah FOO moo FOO boo Can any tell me what I am doing wrong ? I am trying only to replace the match once. eg FOO bah [foo] moo [foo] boo Any help would be appreciated... Cheers John Clegg